The Scientific Report of the 2015 Dietary Guidelines Advisory Committee has just been released. At 571 pages it is a mind boggling compendium of recommendations and data that go far beyond diet alone. It’s useful as a source of information concerning almost every aspect of American life remotely connected with food and health. You want to know about exercise or even how much time you should spend in front of a screen, it’s in the 571 pages. But is this report of any practical use? I’m afraid that despite all the effort and expense that went into it will be read by few and acted upon by even fewer.
Briefly, the report recommends a Mediterranean diet low in sodium, reduced intake of sugar, and regular exercise. There’s much more in the report, but I’ve just presented its essential message. Of course, the report wants much more than I’ve just outlined. Consider this paragraph from it:
It will take concerted, bold action on the part of individuals, families, communities, industry, and government to achieve and maintain healthy dietary patterns and the levels of physical activity needed to promote a healthy U.S. population. This will entail dramatic paradigm shifts in which population health is a national priority and individuals, communities, and the public and private sectors seek together to achieve a population-wide “culture of health” through which healthy lifestyle choices are easy, accessible, affordable and normative—both at home and away from home. In such a culture, preventing diet- and physical activity-related diseases and health problems would be much more highly valued, the resources and services needed to achieve and maintain health would become a realized human right across all population strata, the needs and preferences of the individual would be seriously considered, and individuals and their families/households would be actively engaged in promoting their personal health and managing their preventive health services and activities. Health care and public health professionals would embrace a new leadership role in prevention, convey the importance of lifestyle behavior change to their patients/clients, set model standards for prevention-oriented activities and client/employee services in their own facilities, and manage patient/client referrals to evidence-based nutrition and comprehensive lifestyle services and programs. Communities and relevant sectors of our economy, including food, agriculture, private business, health care (as well as insurance), public health and education, would seek common ground and collaborations in promoting population health. Initiatives would be incentivized to engage communities and health care systems to create integrated and comprehensive approaches to preventing chronic diseases and for weight management. Environmental changes, including policy changes, improved food and beverage standards.
This is a bold call for action by just about everybody in the country. That’s one interpretation. Another is that it’s wildly utopian. What’s missing is a cost-benefit analysis. What gain is expected from the herculean effort required to realize the above? No such analysis is in the report.
Much is made of the high prevalence of obesity in the US and its contributory role in heart disease and type 2 diabetes. The report documents repeatedly what it takes to be the poor diet of many Americans. Implicit throughout the report is the belief that a better diet would result in better health outcomes. This is more a faith based belief rather than one based on solid evidence.
What constitutes obesity itself is in question. The report appears to use the definition given by the CDC:
For adults, overweight and obesity ranges are determined by using weight and height to calculate a number called the “body mass index” (BMI). BMI is used because, for most people, it correlates with their amount of body fat.
An adult who has a BMI between 25 and 29.9 is considered overweight.
An adult who has a BMI of 30 or higher is considered obese.
To calculate a BMI go here. There is serious doubt that the above definitions of overweight and obese are accurate. As I have mentioned previously a recent paper in the Journal of the American Medical Association strongly suggests that a BMI of 25-30 be considered normal and that 30-35 define overweight and that obesity start at a BMI greater than 35. What definition you use to define obesity drastically changes the magnitude and nature of its problem.
Let’s look at a few health outcomes and see if they can disclose the kind of peril the report implies. Despite eating too much red meat, too many calories, too much sugar, and not eating enough grains and vegetables life expectancy in the US is at its highest ever. Deaths from heart disease are at an all time low having fallen more than 50% over the past 30 years.
Though there are more and more data showing that a diet containing not more than 2300 mg of sodium is not beneficial and could even be harmful, the report persists in this recommendation even though it concedes that there is evidence that it’s wrong. I recently wrote about the papers in the New England Journal of Medicine that suggest that the optimum daily intake of sodium is about twice that advised by the report. Salt and More Salt. Even Scientific American has commented on the wrongheadedness of the governments dietary sodium guidelines – “The zealous drive by politicians to limit our salt intake has little basis in science.”
A major modification of the American diet is likely not to happen. The consequences of ignoring most of the recommendations in this report will almost certainly be small to invisible. The recommendations are working on the thin margins of the national health. Doctors in practice whose time is completely consumed by trying to see 32 patients in a day, to get their electronic record system to work, and who are inundated by a tsunami of government mandated forms and regulations will likely not even be aware of the guidelines. A physician who spends a lot of time reading them likely doesn’t see many patients.
Common sense, once again, is the best advice here. Try to keep your weight under reasonable control. Avoid extremes of diet. Take a walk every now and then. Don’t engage in habits or behaviors which are obviously harmful. After these, your fate is in the hands of Fortuna.
When pundits write about a major problems and offer solutions for them, they are typically disappointed when no one acts on their advice. They are ignored, not necessarily because their advice is bad, but rather because any serious problem is so complex that it cannot be fixed as a large constituency is against any solution offered. But if what you recommend is doing nothing you are likely to be rewarded by seeing your advice acted or rather not acted, upon.
You can download the entire report from the link below.